BILLINGS, Mont. (AP) — Yellowstone National Park transferred 20 bison to a Montana Indian tribe for slaughter on Wednesday, marking the first such action this winter under a plan to drastically reduce the size of the largest genetically pure bison population in the U.S.
The transfer was first disclosed by the Buffalo Field Campaign, a wildlife advocacy group, and confirmed by park officials.
Five more bison that had been captured were to be turned over to the U.S. Department of Agriculture on Thursday for use in an experimental animal contraception program, said park spokesman Al Nash.
Yellowstone administrators plan to slaughter up to 600 bison this winter if harsh weather conditions inside the 2.2-million-acre park spur a large migration of the animals to lower elevations in Montana. It's part of a multiyear plan to reduce the population from an estimated 4,600 animals to about 3,000, under an agreement between federal and state officials signed in 2000.
Tens of millions of bison once roamed the North American Plains before overhunting drove them to near extinction by the early 1900s. Yellowstone is one of the few places where they survive in the wild.
James Holt, a member of Idaho's Nez Perce tribe and board member for the Buffalo Field Campaign, said the park's population target was an arbitrary number that threatens to infringe on treaty hunting rights held by his and other tribes. Members of those tribes travel hundreds of miles every winter for the chance to harvest bison.
Holt said many tribes have a sacred, spiritual connection with the animals because American Indians historically depended on them for food and clothing.
"We're talking about the last free-roaming herd here," he said. "It does them a disservice and is a disrespect to them that they are being treated in this manner."
But Montana's livestock industry has little tolerance for bison because of concerns over disease and competition with cattle for grass.
Steps taken by former Montana Gov. Brian Schweitzer to give bison more room to roam outside the park have yielded mixed results, with ranchers and local officials pushing back.
The last major bison slaughter occurred in the winter of 2008, when 1,600 were killed. Schweitzer later placed a temporary moratorium on the practice that has since expired.
The latest group of bison destined for slaughter was transferred to the Confederated Salish and Kootenai tribes.
Nash said hundreds more bison remain clustered near the park's northern boundary, where the 25 animals were captured Friday after they wandered into a holding facility. That sets the stage for potentially more shipments to slaughter in coming days and weeks if more bison start to move into Montana.
"We're set up and ready to go should we see bison come down in significant numbers," Nash said.